Modified proximity criterion for the analysis of the solvation environment of a polyfunctional solute Abstract: The proximity criterion of Mehrotra and Beveridge, that divides the region around a solute into the Voronoi polyhedra defined by the solute atoms, has been modified to use the radical planes based on the solute atom Van der Waals spheres, as suggested by Gellatly and Finney, or on the interaction strength of the atom with the solvent. A comparison of these proximity criteria is given on the aqueous hydration of trans N-methyl acetamide.